You shouldn’t have to be an electrician to learn how to charge your electric car at home.
But, with all the jargon concerning outlets and plugs, it can be challenging for even the most handy owners to understand what’s going on. Here’s what you need to know about the electrical side of charging at home.
Level 1 Charging: using your wall outlet won't cut it.
The common United States outlet we all know well is the standard 110 or 120 volt outlet. This outlet only lets you pull 15 amps of power--what does that mean for you and charging? Well, it’s slow. Which makes sense considering it’s the same outlet you use to charge your phone. A 110/120 outlet will give your car about 3 miles per 1 hour of charging, a rate that would take 3 days to fully charge a Tesla Model 3.
If you see Level 1 or L1 charging used in any electric vehicle literature, that refers to this 110/120 outlet.
Level 2 Charging: once you have it installed, you'll never go back.
Now, onto Level 2 or L2 charging. This faster form of charging comes from a larger outlet (220 volts) that is used for electric dryers, hot tubs, and electric water heaters. You may already have one in your home, but if not, you could have a professional electrician install one.
There are a number of different Level 2 outlets that exist. It's important to know which one you have, that way you can match it with your car charger.
The NEMA 10-30 / 14-30
First, we have the NEMA 10-30, which is an outlet that can be found in older homes. This outlet is a 30 amp circuit (the “30” in 10-30 refers to the amperage!), but whatever you plug into it will only be able to pull 80% of that (24 amps) for safety. And if you’re interested, it uses 5.7 kilowatts.
In normal human terms? The NEMA 10-30 will charge your EV 4x faster than the normal 110/120 outlet, averaging about 15 miles of range per 1 hour of charging.
For newer homes, you’ll likely have a NEMA 14-30 in your home. This is just a newer version of the 10-30, described above.
The fastest outlet at home: the NEMA 14-50.
The NEMA 14-50 is the most common outlet installed for EV chargers. It’s faster than the 10-30, giving you up to 10 more miles of range per hour. The amperage rule applies here, as well: you'll be able to draw 80% of 50 amps, which comes out to 40 amps.
Caution: some gung-ho homeowners will want to install a 14-50 at home by themselves. Your home very well may not be wired to handle 50 amps, even if your breaker says it is. If this is the case and you install a 14-50 outlet, your car charger will try to pull 50 amps when your wiring can only handle 30--this will likely lead to sparking and fires.
Make sure to consult a professional electrician if you’re looking to install or switch out an outlet.
This outlet is rare, but does exist. The 6-50 is an outlet typically used for welders. So, if you have one in your home, then you might be in luck--some EV chargers, like the ChargePoint Home, have a plug for the 6-50. Otherwise, you'll want to get an adapter.
The specs. on this outlet are the same as the 14-50: it has a 50 amp circuit that pulls 40 amps at 9.6 kilowatts, which provides 25 miles of range per 1 of charging.
Other things to know about L2 Charging.
-Don’t use extension cords without consulting an electrician.
Often times the size of the wiring is too thin to handle a 220v outlet, which can lead to sparking and fires. Additionally, using an extension cord for charging is against the National Electric Codes.
-Just because your outlet can provide 24 or 40 amps, the charger built into your car may only be able to handle lower currents.
If you’re interested, look at the details of your EV to see how many amps your car can take. This will give you a better estimate for the maximum amount of miles it will charge per hour.
-How do I get one of these outlets installed? Hire an electrician. Always consult professional help first. But, know that it can be costly with panel upgrades, permits, and fees.
Have more specific questions about your home setup? We'd love to help.
Talk to our home charging expert, Spencer, at (858) 952-8117 or firstname.lastname@example.org.